Bava Kamma

MISHNAH. THE PRINCIPAL CATEGORIES OF DAMAGE  ARE FOUR: THE OX,  THE PIT,  THE 'SPOLIATOR' [MAB'EH]  AND THE FIRE.  THE ASPECTS OF THE OX ARE [IN SOME RESPECTS] NOT [OF SUCH LOW ORDER OF GRAVITY] AS THOSE OF THE 'SPOLIATOR';  NOR ARE [IN OTHER RESPECTS] THOSE OF THE 'SPOLIATOR' [OF SUCH LOW ORDER OF GRAVITY] AS THOSE OF THE OX;  NOR ARE THE ASPECTS OF EITHER OF THEM, IN WHICH THERE IS LIFE, [OF SUCH LOW ORDER OF GRAVITY] AS THOSE OF THE FIRE WHICH IS NOT ENDOWED WITH LIFE;  NOR ARE THE ASPECTS OF ANY OF THESE, THE HABIT OF WHICH IS TO BE MOBILE AND DO DAMAGE, [OF SUCH LOW ORDERS OF GRAVITY] AS THOSE OF THE PIT OF WHICH IT IS NOT THE HABIT TO MOVE ABOUT AND DO DAMAGE.  THE FEATURE COMMON TO THEM ALL IS THAT THEY ARE IN THE HABIT OF DOING DAMAGE; AND THAT THEY HAVE TO BE UNDER YOUR CONTROL SO THAT WHENEVER ANY ONE [OF THEM] DOES DAMAGE THE OFFENDER IS LIABLE TO INDEMNIFY WITH THE BEST OF HIS ESTATE. GEMARA. Seeing that PRINCIPAL CATEGORIES are specified, it must be assumed that there are derivatives. Are the latter equal in law to the former or not? Regarding Sabbath we learnt: The principal classes of prohibited acts are forty less one.  'Principal classes' implies that there must be subordinate classes. Here the latter do in law equal the former; for there is no difference between a principal and a subordinate [prohibited act] with respect either to the law of sin-offering  or to that of capital punishment by stoning.  In what respect then do the two classes differ? — The difference is that if one simultaneously committed either two principal [prohibited] acts or two subordinate acts one is liable [to bring a sin-offering] for each act, whereas if one committed a principal act together with its respective Subordinate, one is liable for one [offering] only. But according to R. Eliezer who imposes the liability [of an offering] for a subordinate act committed along with its Principal,  to begin with why is the one termed 'Principal' and the other 'Subordinate'? — Such acts as were essential in the construction of the Tabernacle are termed 'Principal',  whereas such as were not essential in the construction of the Tabernacle are termed 'Subordinate.' Regarding Defilements we have learnt:  The Primary Defilements: The [Dead] Reptile,  the Semen Virile